Work-holder.



PATBNTED FEB. 20, 1906.

J. W. SPENGE.

WORK HOLDER.

APPLIOATION FILED SEPT. 29, 1905.

NITED STATS 'FFII FFICE.

Specification of Letters Patent.

Patented Feb. 20, 1906.

Application filed September 29. 1905. Serial No. 280,614.

To @ZZ whom t may concern:

Be it known that I, JAMES W. SPENCE, a citizen of the United States, anda resident of Racine, in the county of Racine and State of Wisconsin,have invented certain new and useful Improvements in Engravers Work-Holders and I do hereby declare that the following is a full, clear, andexact description thereof.

The invention consists in certain peculiarities of construction andcombination of parts hereinafter particularly set forth with referenceto the accompanying drawings and subsequently claimed, its object beingto facili-A tate the Work of an engraver by providing means for readyclamping of work of various diameters without marring the edge of same,and a further object is to afford a smooth surface for the thumb of thetool-hand ofsaid engraver.

Figure 1 of the drawings is indicated by line l l in Fig. 2 andrepresents a partly-sectional elevation of the pivotal head of awellknown type of engravers block surmounted by a work-holder inaccordance with my invention, this work holder and the work clampedtherein being wholly in section; Fig. 2, a plan view of the work-holderin the position aforesaid, the work in said holder being partly brokenaway Fig. 3, an elevation of the assemblage aforesaid, partly insection, as indicated by lines 3 3 in Fig. l, Fig. 4, a sectional viewof a fragment of the workholder and work; Fig. 5, a plan view of thechucks of the work-holder inverted; Fig. 6, a perspective view of one ofsaid chucks inverted Figs. 7 and 8, plan views of compressibleinterchangeable work bushings, and Fig. 9 a sectional view of thebushing shown by Fig. 8.

Referring by letter to the drawings, A indicates the pivotal head of anengravers block of ordinary type, B the right and left screw in anangular center slot of said head, and C each of the opposingsemicircular jaws having angular Shanks D in sliding fit with said slotand which constitute nuts on said screw. The jaws are provided with theusual series of vertical resesses that ordinarily serve for thereception of pins between which the work is clamped by screw adjustmentof said jaws but my invention contemplates the employment ofa pair ofchucks in detachable and adjustable connection with the aforesaid jawsand a split springbushing engageable with the chucks to constitute awork-holder. By means of interchangeable bushings the holder can beutilized for work of various diameters.

Each chuck E consists of a segmental block provided with a countersunkupper shoulder Z1, also of segmental contour, on which to support asplit-spring bushing F, within which the Work to be engraved is grippedby an adjustment of the jaws C and chucks surmounting the same. A groovec is provided in the bottom of each chuck for the engagement of a pin d,set in a j aW-recess, and it is preferable to provide said chuck with apermanent depending pin e for the en agement of another jaw-recess, thispin eing approximately in line with said groove that extends lengthwiseof the chuck. However, the pin may be separable from the chuck. Becauseof its groove the chuck is readily attachable to a jaw C withoutparticular reference to what one of a line of recesses in said jaw isoccupied by the pin d, that engages said groove.

To give the split-spring bushings elasticity and cause them by expansionand contraction to circumferentially adjust themselves to varyingdiameters of work being held, the majority of them are made of metalrolled thin and hardfand are provided with inner lugs f, on which toseat the work, and with outer lugs g, that rest upon the shoulders b ofthe chucks; but, as shown in Figs. 8 and 9, the bushing F for thelargest diameter of work has a continuous inner ilangef instead of thelugs f of the other bushings, and all the bushings are preferablyprovided with an inner upper lip h, that laps the work to prevent thesame from crowding out under pressure.

For thin work a supporting-washer G or other suitable spacing device isset in a bushing engaging the chucks, and it will be understood thatsaid work is so held that there are no pins, blocks, or other devices inthe way of the engraver and th at there is always smooth surface forcontact of the thumb of the working hand of said engraver, this being animportant feature of advantage.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. A work-holder consisting of a pair of chucks attachable to theadjustable jaws of an engravers block, and a split-spring bushingconstituting a circumferentially compressible work-support in engagementwith the chucks.

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2. A work-holder consisting of a pair of chucks attachable to theadjustable jaws of an engravers block7 and a split-spring bushing havingan inner upper lip and which constitutes a compressible work-support inengagement with the chucks.

3. A work-holder consisting of a pair of chucks each provided with adepending pin and an under side groove approximately in line one .withthe other, the pin being for engagement of a recess in one of theadjustable jaws of an engravers block and the groove for engagement of apin projecting from the other of said jaws; and a split-spring bushingconstituting a compressible Work-support in engagement with the chucks.

4. A work-holder consisting of a pair of chucks attachable to theadjustable jaws of an engravers block and each having a countersunkupper shoulder of segmental contour, and a split-spring bushingconstituting a work-support on the shoulders of said chucks.

5. A work-holder consisting of a pair of chucks each provided with adependin pin and an under side groove approximaty in line one with theother, the pin being for engagement of a recess in one oi' theadjustable jaws of an engravers block and the groove for engagement of apin projecting Jfrom the other of said jaws.

In testimony that I claim the foregoing I have hereunto set my hand, atRacine, in the county of Racine and State of Wisconsin, in the presenceof two witnesses.

JAMES W. SPENCE.

Witnesses:

W. H. DREW, FRED K. SCHULZ.

